Conveyor useful in a continuous brewing apparatus



R. H. WOHLEB Feb. 22, 1966 CONVEYOR USEFUL IN A CONTINUOUS BREWINGAPPARATUS 2 Sheets-Sheet l Original Filed Feb. l5. 1960 I NVENTOR. 05527Wofa 5 |rHIV 4 fr0/@NEVE R. H. WOHLEB Feb. 22, 1966 CONVEYOR USEFUL IN ACONTINUOUS BREWING APPARATUS 2 Sheets-Sheet 2 Original Filed Feb. l5,1960 ,4 r role/V616 United States Patent O This application Mar. 23,1964, Ser. No. 354,510 16 Claims. (Cl. 99-278) This application -is acontinuation of my application Serial No. 8,769, filed February 15,1960, now abandoned.

This invention concerns the handling and conveying of a material that isprimarily liquid, although it can include solids suspended in orsettling out of the liquid. More especially it concerns continuoushandling and conveying of such material, through zones where additionalliquids or additional solids are added, or are drained olf or separated,and/or where the materials are treated as they advance, as by cooking,sparging, brewing, and the like.

It is a pri-mary purpose of the invention to provide a conveyor for suchmaterial undergoing such treatment that although the opera-tion is acontinuing one, yet will segregate the material into separate batches,and will maintain the batches thus segregated throughout their passagethrough a plant, to the end that during their passage each batch istreated alike, and all arrive at the delivery point like all otherbatches in all respects, and when mixed there will constitute a uniformproduct that `can be duplicated, as may be required, by similartreatment of like products, assuming reasonable uniformity of theingredients.

It is also an object to provide such a conveyor that will be especiallysuited for use in a plant for the continuous brewing of beer, or foranalogous purposes.

Also, it is an object to provide such a conveyor, and such a plantincorporating the same, that shall be simple, inexpensive, reliable, andcompact, and that will require a minimum of investment for any givencapacity.

The invention is incorporated in a conveyor that includes a trough thathas a semi-cylindrical bottom portion, disposed with its axis horizontalor substantially so, as hereinafter explained, with a helical screwconveyor the blade whereof extends in substantially fluid-tightrotational engagement with the semi-cylindrical bottom portion, so thatthe rotational axis of the screw is also substantially horizontal. Thisdivides the space lengthwise of the trough and below the rotative axisinto a plurality of separate compartments that are incapable ofcommunicating one with another so long as care is taken to avoid theliquid level rising to or above the rotative axis. Each such compartmenttravels lengthwise of the trough as the screw rotates, each segregatingits individual batch of liquid material from batches in othercompartments, and each compartment in succession can travel throughzones where the material within it can be heated, drained, added to, orotherwise treated, each compartment individually, yet each identicallywith all other compartments, by a continuous operation of heating,adding draining etc., at fixed stations in the length of the trough,care being taken to prevent overiil-ling of the compartments to or abovethe level o-f the rotative axis. If drainage is required, the troughbotto-m can be perforated at appropriate portions of its length. Ifaddition of liquid to compensate for drainage is required, this can beeffected in appropriate relation to drainage zones. If addition ofsolids is required, this can be effected, uniformly in each compartment,so long as or to the extent that the liquid level does not n'se as `faras the axis of rotation of the screw.v If deepening of a filter bed ofsolids is required, to slow down drainage of liquids in some portion ofthe trough, this can be done by decreasing the pitch 3,236,173 PatentedFeb. 22, 1966 ICC of the screw conveyor in this portion, or by otherappropriate measures.

Such a conveyor will be found suitable for many purposes. It may beuseful in cooking fruits, etc., for canning, or for brewing anddehydrating of coffee in the manufacture of instant coffee. It has beenproposed as especially suited for use in the continuous brewing of beer,from the malt and adjunct peptonizing stage to the hot wort stage, readyfor fermenting, and particularly in each of the lautering and brewingstages, or in those two stages conjointly. It will therefore bedescribed, and its use illustrated, by reference to a continuous beerbrewing apparatus.

The brewing of beer involves many variables. Among these are Variationsin the mineral content of the water supply, in the malt and its grits,in the yadjuncts which are almost always used, in time and temperaturefactors, and in the desired color, taste, strength, and aroma of thebeer. Some of these variables are matters of choice, but others areuncontrollable and variations must be compensated for. Brewing hasheretofore been a batch operation for the most part, since batchoperation lends itself well to proper compensation, to achieve thedesired uniformity of the product, such as is difcult with a continuousprocess. The batch operation is, however, uneconomical in a number ofways.

By use of the conveyor of this invention it is possible to brew beer bya continuous brewing operation, while still maintaining the liquid wortand the solids correctly and uniformly admixed in small batches,certainly in the lautering and brewing stages, and preferably also inthe preceding peptonizing and cooking stage, for the malt and for theadjuncts, and in the mash cooking stage, while maintaining thesuccessive batches segregated and individually distinct, the batchesmixing together not at all or only as they are mixed under conditionswhich insure uniformity as the materials progress through .such stagesor advance to subsequent stages, and the solids in which successivebatches are continuously discharged when spent.

By this invention, by `appropriate modification of the conveyor toaccommodate particular conditions in a given zone, grits or other solidsin the separate batches in individual compartments can be used as filterbeds for the 4liquid material, such as the wort7 `whereby to extractmost fully the desired constituents, and to enable gravity dumping ordischarge of the spent solids (malt and adjuncts, and hops) at the endof each appropriate stage.

Similarly, the beer lean be brewed continuously by the use of theconveyor of this invention, in such a way that control of time andtemperature factors, differing in different parts of a single stage, andin the different stages, can readily be effected, notwithstanding the-contiguity of the different individual lbatches.

The conveyor of this invention is made yflexible and simple, byappropriate modification or rearrangement to accommodate differences in`building layout, kind or type of beer, and the like.

In the accompanying drawings the invention is shown, largelydiagrammatically, incorporated in a typical continuous brewing plant, byway of example. The invention will lbe described in `detail as used forthis purpose. The brewing plant and parts thereof, as well as theconveyor broadly, for whatever purpose it may be used, are considered tobe different aspects of my invention, and both are claimed herein.

FIGURE l is `a side elevational diagram, and FIG- URE 2 is a diagram inplan view, of the typical plant.

.FIGURE 3 is an enlarged vertical axial sectional View of a trough andfeed screw employed in at least certain stages, and FIGURE 4 is atransverse sectional view through the same.

FIGURE 5 is a block diagram, in plan, of the complete plant; FIGURE 6 isa time-temperature graph of the malt peptonizing and cooking stage,coordinated with FIG- URE 5; and FIGURE 7 is a like time-temperaturegraph of the adjunct peptonizing and cooking stage and of all subsequentstages, also coordinated with FIGURE 5.

The 1brewing of beer to include the drawing off of the hot wort involvesfour distinct stages, the initial stage of the four being usually (inthe United States) a double stage, involving the peptonizing and cookingof ground malt in one section, and the peptonizing and cooking ofadjuncts in a parallel or coordinate section, but the two sections arekept distinct because the time and temperature factors are different inthe two parallel sections, the finished products whereof are then mixedat the initiation of the second stage, mash cooking. The brewers ofbeers of cer-tain types do not use adjuncts, hence in such cases the useof this section can be dispensed with. After the second, mash cooking,stage the brew goes through the thi-rd or lautering stage, where wateris added, and filtered out wort is readded, and at the ends of th-atthird stage the wort is filtered or drained out and the spent mash isdischarged. The Wort proceeds to the fourth,

brewing stage, where hops are added, and at the conclusion of thebrewing stage the hot wort is drained and delivered to the hot worttank, and spent hops are discharged. In the usual brewing operation abatch proceeds as a unit lay means of valve-controlled conduits, openonly during transfer, from one tub or kettle to the next, in each ofwhich the batch rests while the complete stage is performed.

Illustrating use of the present invention in continuous brewing, ascontrasted to the usual batch brewing, hot water and ground malt gritsare continuously supplied in measured quantities and desired ratio tothe initial stage A, or to one of two parallel sections thereof A1 orA2, and hot water and adjuncts are similarly supplied to the other suchsection. rlhese constituents are desirably segregated immediately intosucces-sive and uniform batches, and after admixture of the products ofthe two parallel sections, at the end of the first stage proceed, againas successive and uniform individual batches, through the second, third,and fourth stages. Withdrawals and admissions occur in the lautering,and the brewing stages, but are accomplished in a manner to maintain theuniformity of the segregated individal batches. The stages A, B, and Care shown substantially in alignment, and the stage D as reversed andbenath stage C, but this is a matter that will be determined by theplant layout, and no particular orientation or .arrangement of stagesrelative to one another is essential to the invention.

More particularly, the liquid and the solids entrained there-with aretransported through the several stages in troughs 1 such as that sholwnin FIGURES 3 and 4, and designated 1C, of semi-cylindrical form at thebottom 10, within which a helical feed screw 2 is disposed, fittingclosely against and coaxial with the bottom 10. This defines individualcompartments below the level of the rotative axis. The trough and feedscrew are disposed substantially horizontally, lso that there is notendency for liquid to spill lengthwise from one compartment to thenext. Preferably the outer ed-ge of the screw is fitted with a wiperstrip 21, engaging the semi-cylindrical bottom of the trough, and sincethe screw blade is continuous from its axis 20 to its outer edge, itfollows that each compartment defined between successive turns, andbelow its axis, is wholly separate from all other such compartments.Care is taken to avoid filling to or above the axis, as FIG- URE 4shows, hence each compartment contains an ndividual batch, kept separatefrom all other batches, and advanced, by unidirectional rotation of thefeed screw, from one end of the trough 1 to the other end. By supplyingliquids and solids at a constant Vand controlled rate using meteringvalves or other like controls, at fixed stations, and by maintaining thefeed screw rotating at a constant rate, each batch is identical withevery other. By regulating temperature factor-s at different parts ofthe length of the trough each batch is heated alike, and time factorscan be regulated by such means as controlling the rate of rotation ofthe screw, or varying the pitch thereof in different parts of itslength.

By way of example, in the initial section A, or A1 or A2, hot water issupplied at 31, 32, at a rate coordinated with the size and rate ofadvance of the screws 2 in the sections A1 and A2 respectively. Groundmalt from hopper 4,1 and metered at 42 is supplied into the trough ofsection A1 at a constant rate, and adjuncts, if the brewer requiresthem, is supplied from a hopper 43, like- Wise in metered and constantamounts, to the trough of section A2. The two troughs are heated at 51,52 respectively to bring the malt and the adjuncts to and to hold themat the desired cooking temperatures, after being, in some cases,peptonized first by the initially supplied hot water.

The cooked malt and adjuncts are then delivered, as by a right-and-leftfeed screw 22, to the second stage B. Here, after thorough mixing by thescrew 22 they are delivered into the trough of stage B, which todistinguish it is designated 1B, in the initial portion whereof theirmixing is completed. The screw of this section may be modified at thisend, as by perforations, or diameter, pitch, etc., to effect suchmixing, if desired. The soconstituted mash is then divided by the feedscrew 2 in stage B into successive separate batches, and is advancedtowards the opposite end of the mash cooking stage. Heat is supplied, asby the steam jacket 54 in the initial portion of this stage, to maintainthe desired temperature, and extra heat can be supplied similarly, as isindicated at 55 in the later brewing stage, to raise the temperature toa proper mashing-off valve upon completion o-f sacclrarifi'cation. Thiselevated temperature should be held for a time, to which end insulationas at 53 may sufiice, or enough heat may be added to counter any heatloss. Throughout the system such expedients (insulation or addition ofheat to compensate for heat loss) may be used as required, although notelsewhere specifically shown.

The cooked mash continues into the lautering stage C, and the feed screwand trough (the latter designated 1C to distinguish it from the trough1B of the mash cooking stage) may be continuous through the stages B andC. In the lautering stage the wort is normally drained gradually fromthe mash and filtered again through the same, and sparging water issimilarly sprayed upon and filtered through the mash. Care is taken toavoid supplying liquid in quantities to raise the level to the rotativeaxis. The solids must be allowed to settle upon the bottom 10 of thetrough, and this bottom should be perforated, as by the small slits 11(see FIGURES 3 and 4) to drain off liquid and so to make space toreceive added liquid. Liquid wort filtered out and drained through theslits may be pumped from the drainage sump 61 by a pump 6 and returnedas a sparging liquid by way of spray apertures at 62. Sparging water issupplied by sprays at 63, and the drained-off wort from sumps 60 isdelivered by conduits 7 to the start of the brewing stage D. Beyond thelast sump 60 a chute 81 is provided to receive and dispose of the spentmash, which the feed screw delivers to that chute.

It will be noted, at the end of the lautering section, that the pitch ofthe feed screw 2 is lessened at 25. This has the effect of deepening thefilter bed of spent mash, by squeezing it in the axial direction. Thetendency to deepen the filter bed and to lessen the volume of eachindividual batch tends to maintain the depth of each batch nearlyconstant, until the last extract is drained off, and improves theefficiency of extraction. The final, nearly dry spent mash is removed at81.

In the brewing stage, as in the lautering stage, the liquid wort andsolids being treated are maintained in successive batches, uniformlyconstituted. The wort is supplied by way of conduits 7 from thelautering stage and metered for supply at a constant rate, is heated bya heater such as the steam jacket 55, and hops are added from hoppers(not shown) by way of inlets 91, 92 at appropriate points in the lengthof the trough, and in metered constant amounts in correct ratio to thewort. At the terminus of the brewing stage trough, designated 1D todistinguish it, its bottom is perforated, as at 11a, and the hot wortdrains out and is delivered by conduit 74P, assisted if need be by pump71, to the hot wort tank or coolship (not shown). Additional hotsparging water, as needed, is added at 64. The spent hops continue withthe screw and are dumped into the chute 82 for disposal. At the end ofthe brewing stage the pitch of the feed screw is decreased, as at 26,with similar results as in the lautering stage.

The processing of the wort thereafter, as the -fermenting etc., isconventional, and is no part of this invention.

Slight reference has been made hereinbefore to time and temperaturefactors as regulated in the described process and apparatus. Thesefactors are regulated by the brew master to suit his preference or inaccordance with his experience, hence no hard and fast rule can begiven, but coordinated FIGURES 5, 6 and 7 show a typical plan. FGURE 5blocks out the four stages in a continuous line, and FIGURE 6illustrates the timetemperature graph of a typical malt peptonizing andcooking stage A1, while FIGURE 7 in the corresponding portion shows asimilar graph of a typical and complemental adjunct peptonizing andcooking stage A2. The two end products, mixing, have an intermediatetemperature. This is held for a period of time and then raised sharplyto a temperature suitable to halt the mashing action, at mashing-off, inthe mash cooking stage, shown in FIGURE 7, and this raised temperatureis maintained in the lautering stage. The temperature is again raisedand maintained in the brewing stage. All such time and temperaturefactors can be suited to the known rate of advance and length of thefeed screws, and the known capacity of the chambers between successivehelices of the screws. Temperature can be raised by suitable heaters,such as steam jackets, and held, as by insulation.

The conveyor has been described as it would be employed in thecontinuous brewing of beer. This illustrates in the different stages thevarious modifications it may undergo in various parts of its length toaccommodate differing conditions, but the concept of segregating batchesin individual noncommunicating compartments of a horizontally-disposedrotative helical screw conveyor wiping in substantially liquid-tightcontact with the semicylindrical bottom of a trough, with the liquidlevel never permitted to rise to the level of the rotative axis, remainsthe same, and can be used for various purposes. Depending upon somespecific purpose, the liquid can be drained from the trough,replenished, or readded to maintain the liquid level substantiallyconstant, or solids can be added, or separated out by filtration ordrainage, and time and temperature factors can be controlled. Eachbatch, in the individual compartments, is kept segregated from all otherbatches, yet each batch as it advances is subjected to the sametreatment as are all the others, and the end result is uniformity of thetreated products.

Accordingly, in its broader aspects the invention concerns a conveyorfor whatever purpose, and in a specific aspect concerns a continuousbrewing plant as a whole, and more particularly the lautering and/ orthe brewing stages thereof.

It should be pointed out again that it is essential to this inventionthat the trough be so disposed that it is So nearly horizontal that noliquid can spill lengthwise from one compartment to another. This doesnot depend appreciably upon the depth to which the compartments arelled, for with any appreciable inclination liquid will tend to spill atthe sides of the screw. Moreover, since it is intended that thecompartments be filled almost to the level of the rotative axis of thescrew, for operation at maximum capacity, it is clear that anysubstantial departure from horizontal will defeat the purpose of theconveyor, and will tend to spill the contents, which are primarilyliquid, from one compartment to the next lower, and will destroy theuniformity of the several batches. It is clear, also, that even solidcontents should be kept below the level of the rotative axis, for ifsolids extend above that level they will tend to spill from onecompartment to another, or liquid entrained with or absorbed by thesolids will also tend to spill, in either case destroying the uniformityof the individual but separate batches.

I claim as my invention:

1. A conveyor for a material which is primarily a liquid, comprising ascrew conveyor formed with a helical blade, and disposed with its axishorizontal, a trough encircling the bottom half of said blade, insubstantially liquid-tight engagement with the same throughout thelength of the blade, to define noncommunicating individualsemi-cylindrical compartments entirely below the level of the bladesaxis, the sides of the trough extending upwardly to a somewhat higherlevel, out of contact with the blade, means to rotate said bladeunidirectionally within its trough, to advance the compartmentslengthwise of the trough, and fixed positioned means to delivermaterials, including liquid, to the trough in quantities not exceedingthe capacity of each individual Semi-cylindrical compartment as thecompartments advance past said delivering means, whereby the level ofliquid is always below the blades axis.

2. A conveyor as in claim 1 wherein the troughs bottom portion isnon-perforate, and hence liquid-impervious, in the region of theliquid-delivering means, and thence throughout at least the majorportion of its length.

3. A liquid conveyor according to claim il wherein the trough bottom isperforated at its final end portion as a strainer and the screw conveyoris of reduced pitch in the same end portion of the trough, relative tothe pitch thereof in the remainder of said trough, to slow the rate ofadvance of the solids strained from the liquid, and to deepen the filterbed formed thereby.

4. A liquid conveyor comprising casing means defining a substantiallyhorizontal trough having a semicylindrical bottom portion and sidesdirected upwardly generally tangentially, at least a major portion ofthe length of said semi-cylindrical trough bottom portion beingnon-perforate and hence of liquid-impervious construction, a screwconveyor mounted coaxially with said trough bottom portion forunidirectional rotation therewithin, said screw conveyor having a bladeextending helically thereabout at a helix radius substantially equal tothe radiusl of said bottom portion about their common axis, to effectHuid-tight rotational engagement between said blade and said bottomportion and thereby to divide said trough bottom portion, below its axisand below its sides, into a series of individual, non-communicating,semi-cylindrical, and axially advancing compartments, and means forintroducing a selected quantity of material, including liquid, less thanthe capacity of an individual compartment, to each successivecompartment as the conveyor is rotated.

5. A liquid conveyor according to claim 4 wherein one end portion onlyof the trough has perforations in the bottom portion thereof forliquids-solids separation.

6. A conveyor as in claim 5, including additionally inlet means disposedat locations in the length of the trough which have the non-perforatebottom portion, for introducing solids to the successive compartments,in quantities consonant with the amount of liquid in each thereof, butinsuiiicient to raise the liquid level above the axis of the screwconveyor.

7. In a plant for the continuous brewing of beer by the successivestages of malt peptonizing and cooking, mash cooking, lautering, andbrewing, conveyor mechanism incorporated in at least the lautering andbrewing sections for advancing liquids with entrained solidstherethrough, said conveying mechanism comprising casing means defininga generally horizontal trough having a substantially semi-cylindricalbottom portion with sides directed upwardly therefrom, said bottomportion in the lautering section being perforated, but a major portionof the length of said semi-cylindrical bottom portion in the brewingsection being non-perforate and hence of liquidimpervious construction,screw conveyor means mounted lengthwise of the trough in each sectionfor rotation therewithin, said screw conveyor means having a bladeextending helically thereabout in fluid-tight rotational engagement withthe semi-cylindrical bottom of said trough to form a series ofsuccessive individual semicylindrical compartments along the length ofsaid trough bottom portion Aand lbelow the blades axis, means to rotatesaid screw conveyor means unidirectionally, means at a fixed locationin' advance of the lautering section for introducing a predeterminedquantity of such liquid, less than the capacity of a compartment, toeach successive compartment as the conveyor is rotated and thesuccessive compartments advance unidirectionally past such location, andmeans in the lautering section to introduce sparging liquid to thecompartments approximately sufficient in volume to maintain the liquidlevel lin the several compartments generally constant, despitefiltration of the wort through the perforations in the lauteringsection.

8. A plant according to claim 7, including means at the exit end of thelautering section for deepening the bed of entrained solids in ithecompartments, to assist in maintaining the liquid level inpreceding'compartments.

9. A plant according to claim 7,` including means for collecting and forreturning, as at least a part of the sparging liquid introduced to thecompartments, wort filtered through the perforated bottom of the'troughin the lautering section.

10. A plant according to claim 7, including means for collecting andintroducing at the entrance to the brewing section the wort filtered outin the lautering sectionfin quantities lsutliicent to till successivecompartments therein to a level not higher than' the axis of the screwconveyor means, and means for introducing hops to successivecompartments of the brewing section, in its portion with imperforatebottom, in quantities insulicient to raise the level of the liquid wortabove the Vaxis ofv the screw conveyor.

11. A plant according to claim 410, including means at the perforatebottom portion of the brewing section to deepen and compress the solids,to expel the liquid, v'prior to discharge of the solids.

12. In a plant for the continuous brewing of beer by the successivestages of malt pcptonizing and cooking, mash cooking, lautering, andbrewing, conveyor mechanism incorporated in at least lthe brewingsection for yadvancing liquids with entrained solids therethrough, saidconveyor mechanism comprising casing means defining a substantiallyhorizontal trough having la substantially semi-cylindrical bottomportion, the major portion of its length, in its initial portion, beingnon-perforate and hence of liquid-impervious construction, but beingperforated in its final portion for drainage of liquid, screw conveyormeans mounted lengthwise of said trough for rotation therewithin, saidscrew conveyor means having a blade extending helically thereabout influid-tight rotational engagement with the semi-cylindrical bottom ofthe trough, to form a series of successive individual semicylindricalcompartments along the length of 'said trough bottom portion, means torotate said screw conveyor means unidirectionally, means to maintaineach comrotative axis, and means located in the initial portion of thetrough to admit hops into each successive compartment, las thecompartments advance, in amounts to`preclude raising the liquid level asyhigh as the rotative axis.

13. A plant as in claim 12, including means to slow the rate of advanceof the hops in the perforated final portion of the trough, to deepen thefilter bed formed thereby during drainage of the liquid wort.

14. 4In a plant for the continuous brewing of beer by the successivestages of malt peptonizing and cooking, mash cooking, lautering, andbrewing, conveyor mechanism incorporated in at least the lauteringsection for advancing liquidsy with entrained solids therethrough, saidconveyor mechanism comprising casing means de- .fining a substantiallyhorizontal trough having a substantially semi-cylindrical bottomportion, and perforated for `drainage of liquid at a predetermined rate,a screw conpartment throughout the initial portion of the trough,

filled with liquid to a level below the screw conveyors veyor meansmounted lengthwise of the trough for rotation therewithin, said screwconveyor means having a blade extending helically thereabout influid-tight rotational engagement with the semi-cylindrical bottom ofsaid trough to form a series of successive individual semicylindricalcompartments along the length of said trough bottom portion, means torotate said screw conveyor means unidirectionally, means at fixedlocations in the length of the trough for introducing liquid at a ratesuch,

. in relation to the rate of drainage from the trough, that nocompartment is overfilled as high as the rotative axis of the screwconveyor means, but the liquid level in each compartment is maintainedsubstantially constant, at a level below s uch rotative axis.

15. A plant as in claim 14, wherein there are two separate liquidintroducing means, one in the initial portion of the trough forreintroducing drained off liquid wort, and another in the final portionof the trough for introducing sparging liquid each at a rate to maintainthe successive compartments substantially equally filled.

`16A conveyor for a material which is primarily a liquid, comprising ascrew conveyor formed with a helical blade, and disposed with'its axishorizontal, a trough encircling the bottom half of the blade, insubstantially liquid-tight engagement with the same throughout thelength of the blade, to den-e, at a level entirely below the level ofthe blades axis, a plurality of individual, noncommunicatingsemi-cylindrical compartments, means to rotate the bladeunidirectionally within its trough, whereby such compartments advancelengthwise of the trough, and f ixedly positioned means to delivermaterial, including liquid, into the trough in quantities insuficient toll any compartment to the level of the blades axis, but in likequantities in the several compartments.

References Cited by the Examiner UNITED STATES PATENTS References Citedby the Applicant UNITED STATES PATENTS 5/1933 Buff. 1/1936 Carter.

WALTER A. SCHEEL, Primary Examiner.

WILLIAM B. PENN, ROBERT E. PULFREY,

Examiners. S. P. FISHER, Assistant Examinez'.

16. A CONVEYOR FOR A MATERIAL WHICH IS PRIMARILY A LIQUID, COMPRISING ASCREW CONVEYOR FORMED WITH A HELICAL BLADE, AND DISPOSED WITH ITS AXISHORIZONTAL, A TROUGH ENCIRCLING THE BOTTOM HALF OF THE BLADE, INSUBSTANTIALLY LIQUID-TIGHT ENGAGEMENT WITH THE SAME THROUGHOUT THELENGTH OF THE BLADE, TO DEFINE, AT A LEVEL ENTIRELY BELOW THE LEVEL OFTHE BLADE''S AXIS, A PLURALITY OF INDIVIDUAL, NONCOMMUNICATINGSEMI-CYLINDRICAL COMPARTMENTS, MEANS TO ROTATE THE BLADEUNIDIRECTIONALLY WITHIN ITS TROUGH, WHEREBY SUCH COMPARTEMTNS ADVANCELENGTHWISE OF THE TROUGH, AND FIXEDLY POSITIONED MEANS TO DELIVERMATERIAL, INCLUDING LIQUID, INTO THE TROUGH IN QUANTITIES INSUFFICIENTTO FILL ANY COMPARTMENTS TO THE LEVEL OF THE BLADE''S AXIS, BUT IN LIKEQUANTITIES IN THE SEVERAL COMPARTMENTS.